Centrifugal clutch



Aug- 9.), 1932 n L w. RAwsoN 1,870,649

CENTRIFUGAL CLUTCH Filed July 17. 1931 Patented Aug.. 9, 1932 UNITEDSTATES PATENT OFFICE LOUIS W. RAWSON, OF WORCESTER, MASSACHUSETTS,ASSIGNOR TO WORCESTER POLY- TECHNIC INSTITUTE, OF WORCESTER,MASSACHUSETTS, A CORPORATION F MASSA- CHUSETTS CEN TRIFUGAL CLUTCHApplication led July 17, 1931. Serial No. 551,452.

This invention relates to clutches for connecting a driving rotatingmember to a driven rotating member, and particularly to a type of clutchin which separate sets of centrifugal members are provided on thedriving and the driven members, these two sets of centrifugal membersbecoming operative successively.

Itis the general object of my present invention to improve theconstruction of such clutches by providing improved devices forwithdrawing the centrifugal members from operative position when thespeed of rotation of either or both members falls below a pre`determined point.

My invention further relates to arrangements and combinations of partswhich will be hereinafter described and more particularly lpointed outin the appended claims.

' preferred form of the invention is shown in the drawing, in which Fig.1 is a sectional side elevation of my improved clutch, and

Fig.- 2 is a sectional end view, taken along the line 2-2 in Fig. 1. y

Referring to the drawing, I have shown a centrifugal clutch comprising aclutch member provided with a hub portion 11 fixed to a drivlng shaft12, and a clutch member 13 having a hub portion 14 secured to a drivenshaft 15.

The clutch member 10 is provided with an annular fiange projecting fromthe inner l i face thereof, and with a plurality of radially disposedpartition members 2 1 extending out- Ward from the annular flange 20 andsymthereof.

The clutch member 13 is `provided withan outer annular fiange 30surrounding the clutch member 10 and is also provided with short radialpartition members 31 extending outward from the hub 14 and just clearingthe inner surface of the` annular fiange 20 on the clutch member 10.

Centrifugal members 34 are mounted be` tween the radialpartition members21 on the casing member 10, and centrifugal members 35 are mountedbetween the radial partition members 21 on the hub 14.

Each centrifugal member 34 or 35 is proabout the peripheryvided with aleaf spring 40 of resilient sheet metal, which springsv preferablyextend through wire loops 31 inserted in the members 34 or 35 andypreferably secured therein by embedding the loops in the mold before themembers are cast, so that the molten metal will fiow around the offsetends of the loops and firmly secure the same in position.

The ends of the spring 40 extend under cross plates 44 inserted in thepartition members 21 and 31 and preferably secured therein by being castin position, as previously described for the wire loops 41.

The cross plates 44 serve to tension the springs 40 as the members 34 or35 move outward under centrifugal force, and they also serve to limitthe movement of withdrawal of the members by the springs 40.

It will be noted that the centrifugal inembers 35 on the driven clutchmember 13 are surface of the flange 20 on the driving clutch member10While the centrifugal members 34 mounted on the driving clutch member10 are positioned to engage the inner cylindrical surface of the flange30 of the driven clutch member 13.

Having described the details of construction of my improved clutch, themethod of `operation thereof is as follows:

Assuming that the driven shaft 15 is standing still and that the drivingshaft 12 is placed in rotation, the centrifugal members 34 will berotated with the shaft 12 and with the driving clutch member 10 untilthe speed has increased to a point Where the centrifugal force developedbythe members 34 is suicient to overcome the tension of their springs40.

When this speed is reached, the centrifugal members 34 will engage theinner surfaceof the iange-30 of the driven clutch member 13,

thus starting the driven member in rotation.

ing out and engaging the inner cylindrical surface of the flange 20 ontheI driving clutch member 10, thereby increasing the frictional drivingstrength of the clutch.

lthe adjacent cylindrical surface, so that there is no drag of thecentrifugal members when the clutch is running idle.

In many instances the springs 40 associated with the centrifugal members35 on the driven member may be omitted, but in other cases it isdesirable to use springs on both sets of centrifugal'members Thewithdrawal of the centrifugal members at relatively low speeds isparticularly A. important with respect to the members 34 carried by thedriving clutch member 10, as in cases where the driving member has bothhigh and low speeds and it is desired to rotate the driven member withthe driving member at high speed but to allow the driven member toremain stationary when the driving member is rotated at a predeterminedlow speed. In 4such cases, my centrifugal clutch has all of theadvantages of an over-running clutch, in addition to its frictionaloperation.

By selecting springs 4() of suitable size and strength, the criticalspeed below which the members will be withdrawn may be predetermined asdesired.

KHaving thus described my invention and the advantages thereof, I dolnotwish to be limited to the details herein disclosed, otherwise than asset forth in the claims, but what I claim is l. A centrifugal clutchcomprising a driving and a driven clutch member, each having an axiallyprojecting annular flange, a plurality of radiall disposed partitionsspaced to form a circu ar series of pockets on each clutch member, acentrifugal member mounted for outward movement in each pocket bycentrifugal force and -positionedto engage the inner surface of theflange on the other clutch member when thus movedv outward, certain ofsaid members having leaf springs secured to the inner side thereof andcross plates in said partitions extending over and engaging the endportions of the surfaces of said leaf springs and increasing the sprmgtension thereof as the centrifugal members'l springs extending throughand secured bysaid loops and thereby held adjacent said inner surface,and abutments on said partitions engaging the outer end portions only ofthe outer surfaces of said leaf springs and increasing the springtension thereof as the centrifugal members move outward.

In testimony whereof I have hereunto affixed my signature.

LOUIS W. RAIVSON.

certain of said: members having loops embedded in their inner concavesurfaces, leaf

